Pressure-based battery ejection system

ABSTRACT

A battery ejection system is disclosed. The battery ejection system comprises a pressure vessel, a battery submodule positioned at least partway in the pressure vessel and configured to release gas into the pressure vessel, and a seal of the pressure vessel configured to release in the event a pressure level in the pressure vessel exceeds a threshold pressure level. The battery submodule is configured to be ejected from an electrical connection in the event the seal is released.

BACKGROUND OF THE INVENTION

In the event of a battery malfunction such as cell thermal runaway,batteries may produce hazardous gases and/or large amounts of heat.Techniques to detect and handle malfunctioning batteries would bedesirable.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are disclosed in the followingdetailed description and the accompanying drawings.

FIG. 1A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system prior to battery ejection.

FIG. 1B is a diagram illustrating an embodiment of a pressure-basedbattery ejection system after battery ejection.

FIG. 2A is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising a latch and o-rings prior to batteryejection.

FIG. 2B is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising a latch and o-rings after batteryejection.

FIG. 3A is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising bolts prior to battery ejection.

FIG. 3B is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising bolts after battery ejection.

FIG. 4A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising magnets prior to battery ejection.

FIG. 4B is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising magnets after battery ejection.

FIG. 5A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising shear o-rings prior to batteryejection.

FIG. 5B is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising shear o-rings after battery ejection.

FIG. 6A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising an orifice in the pressure cavity.

FIG. 6B is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising an exhaust monitor.

FIG. 7 is a flow diagram illustrating an embodiment of an exhaustmonitoring process.

FIG. 8A is a diagram illustrating an embodiment of a spring contactelectrical connection.

FIG. 8B is a diagram illustrating an embodiment of a blade and springelectrical connection.

FIG. 9 is a diagram illustrating an embodiment of an aircraft comprisinga pressure-based battery ejection system.

FIG. 10 is a diagram illustrating an embodiment of a barrier betweenbatteries.

FIG. 11A is a diagram illustrating an embodiment of a latch prior tobattery ejection.

FIG. 11B is a diagram illustrating an embodiment of a deployed latchthat prevents a neighbor battery from ejecting.

DETAILED DESCRIPTION

The invention can be implemented in numerous ways, including as aprocess; an apparatus; a system; a composition of matter; a computerprogram product embodied on a computer readable storage medium; and/or aprocessor, such as a processor configured to execute instructions storedon and/or provided by a memory coupled to the processor. In thisspecification, these implementations, or any other form that theinvention may take, may be referred to as techniques. In general, theorder of the steps of disclosed processes may be altered within thescope of the invention. Unless stated otherwise, a component such as aprocessor or a memory described as being configured to perform a taskmay be implemented as a general component that is temporarily configuredto perform the task at a given time or a specific component that ismanufactured to perform the task. As used herein, the term ‘processor’refers to one or more devices, circuits, and/or processing coresconfigured to process data, such as computer program instructions.

A detailed description of one or more embodiments of the invention isprovided below along with accompanying figures that illustrate theprinciples of the invention. The invention is described in connectionwith such embodiments, but the invention is not limited to anyembodiment. The scope of the invention is limited only by the claims andthe invention encompasses numerous alternatives, modifications andequivalents. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding of theinvention. These details are provided for the purpose of example and theinvention may be practiced according to the claims without some or allof these specific details. For the purpose of clarity, technicalmaterial that is known in the technical fields related to the inventionhas not been described in detail so that the invention is notunnecessarily obscured.

A battery ejection system is disclosed. The battery ejection systemcomprises a pressure vessel, a battery submodule positioned at leastpartially in the pressure vessel and configured to release gas into thepressure vessel, and a seal. The seal is configured to seal the pressurevessel in a first mode and is configured to release in a second mode.The second mode is triggered in the event a pressure level in thepressure vessel exceeds a threshold pressure level. The battery isconfigured to be disconnected from an electrical connection in thesecond mode.

In some embodiments, a pressure vessel includes or is a cavity which isformed by a structure and a battery of the battery ejection system ispartially or completely sealed in such a cavity. In some embodiments, anelectrical contact of the battery is positioned within the cavity. Forexample, the battery is connected to a wire or any other appropriateelectrical component within the cavity. In the event of battery failureor malfunction, the battery may vent gases. In some embodiments, thebattery is positioned in the cavity such that vented gases from thebattery release into the cavity. In the event pressure in the cavityexceeds a threshold pressure that a seal of the cavity is designed tohandle, the seal will release. In some embodiments, the battery isejected from its electrical connection in the event the seal releases.For example, the seal holds the battery in the cavity to make electricalcontact and the battery falls from the cavity in absence of the seal. Insome embodiments, the force of the vented gas pushes the battery out ofthe cavity and ejects the battery electrically.

In some embodiments, a battery ejection system is used in an electricaircraft. An electric aircraft powered by batteries may require alightweight system of detecting malfunctioning batteries and removingthem from the aircraft's electrical systems. The pressure-based batteryejection system automatically electrically ejects batteries based on anamount of venting gases, which is a measure of battery malfunction. Forexample, a battery may release gases when it malfunctions whereas aproperly functioning battery does not release gases or releases a lowvolume of gases. Active monitoring and ejection using monitors, gauges,processors, or other heavy equipment is not required. In someembodiments, the battery ejection system provides a reliable, safe,simple, and lightweight way of electrically ejecting malfunctioningbatteries.

FIG. 1A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system prior to battery ejection. In the example shown,battery 100 is positioned inside structure 102. Structure 102 maycomprise part of an electrical load (or electrical connection to such anelectrical load) that battery 100 provides power to. For example,structure 102 may comprise an aircraft framework. In the example shown,seal 106 between structure 102 and battery 100 creates cavity orpressure vessel 104. The seal as shown is positioned near one end of thebattery, leaving a small portion of the battery unsealed. In someembodiments, the battery is configured to vent gases from a portion ofthe battery that is sealed in the cavity. In some embodiments, thebattery includes a covering that directs gas released by the battery.For example, the battery may be stored in a can that has venting slotsthat direct where gas released from the battery may travel; such slotsmay direct any released gases from battery 100 into pressure vessel 104.

As shown, the battery has an electrical connection at the end of thebattery that is pointing into cavity 104. The electrical connection ispositioned at one end of the battery whereas the seal is positioned nearthe midsection of the battery (at least in this example). Battery 100has an electrical connection with structure 102. In some embodiments,the electrical connection comprises wiring that allows the battery toprovide or draw power. In some embodiments (not shown here), seal 106does not wrap around the midsection of the battery but rather surroundsthe battery such that all of the battery is within or otherwiseenveloped by the cavity or pressure seal (e.g., seal 106 goes below orunderneath battery 100). In some embodiments, the battery touches or isin contact with structure 102 at some portions of the battery such thatthere is no need for a seal where they make contact. For example, seal106 may comprise discrete pieces of material that seal multiple gapsbetween battery 100 and structure 102.

In the event a battery fails, it may release gases. In some embodiments,vented gases are released into cavity 104. In some embodiments, seal 106is designed to withstand up to a threshold level of pressure. Thethreshold level of pressure may be determined based on a level ofbattery malfunction that is critical. For example, using a slightlyventing battery may be safer than ejecting the slightly venting batteryand flying with less power in some cases of electric aircraft flight. Abattery venting a large volume of gas and/or a lot of heat may pose alarger risk where it is worthwhile to eject the battery. The thresholdlevel of pressure of the seal may map to an amount of gas corresponds toa high risk battery which cannot be used any longer. In the eventpressure inside cavity 104 exceeds a threshold pressure of seal 106, theseal releases. In some embodiments, the pressure provides a force thatejects the battery from structure 102. In some embodiments, the releaseof the seal allows the battery to disconnect from its electricalconnection. For example, gravity may cause the battery to fall fromstructure 102.

In the example shown, battery 100 is positioned under structure 102. Insome embodiments, battery 100 is positioned atop structure 102. In someembodiments, the battery and structure are positioned on their sides(e.g. FIG. 1B is rotated 90 degrees). In all the examples shown, thepositioning of the battery and structure may be implemented in a rotatedorientation from what is illustrated. Regardless of the orientation, anyventing slots (not shown) in a battery's can may be oriented to befacing upwards. This is because the emitted gases may be hot and riseupwards as a result. Venting slots which are positioned or otherwiseoriented to be facing upward will more readily permit the hot gases toexit into the cavity or pressure vessel.

FIG. 1B is a diagram illustrating an embodiment of a pressure-basedbattery ejection system after battery ejection. In the example shown,seal 106 of FIG. 1A has released. In various embodiments, the sealruptures or is pushed off intact. Release of the seal causes battery 100to be ejected from its electrical connection with structure 102. In someembodiments, battery 100 is ejected from a high power electricalconnection.

In some embodiments, seal 106 is reversible or replaceable. Battery 100may be replaced with a new battery by removing the seal, placing a newbattery in position such that it establishes electrical contact withstructure 102, and replacing the seal or putting a new seal in place.

FIG. 2A is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising a latch and o-rings prior to batteryejection. In various embodiments, various configurations andcombinations of seals are used in the pressure-based battery ejectionsystem. In some embodiments, various components are used in combinationto create the pressure vessel. The various components may performseparate functions. For example, one component may be used to hold thebattery in a position wherein it maintains an electrical connection. Thecomponent may exert a force on the battery that pushes an electricalcontact of the battery against an electrical contact of an electricalload it powers. The component may restrain the battery within astructure. Another component may be used to create an airtight sealaround at least a portion of the battery and the structure.

In the example shown, battery 200 is positioned within structure 202.Battery 200 is held in place by latch 208. In some embodiments, latch208 keeps battery 200 in electrical contact with structure 202. Thelatch may comprise a force-regulating latch that has zero deflectionunder force until it buckles and completely releases when subjected to athreshold amount of force. The latch may comprise a piece of bowed metalthat springs from one stable position to another stable position aftersubjected to a large amount of force. A bistable spring mechanism may beused. In some embodiments, a latch or spring that has two stablepositions and changes from one stable position to a second stableposition after a certain amount of pressure is exerted is used, whereinone stable position causes the latch or spring to hold the battery inthe cavity and another stable position releases the battery. In someembodiments, the latch or spring comprises a flattened portion that isattached to the structure (e.g. structure 202). The rest of the latch orspring may pivot around the flattened portion.

In the example shown, o-rings 204 and 210 are positioned between battery200 and structure 202. In some embodiments, the o-rings create anairtight barrier but are not strong enough to hold battery 200 in place.For example, the o-rings may comprise a flexible material such asrubber. In the example shown, the o-rings are held in place via indentsin structure 202. As shown, o-rings 204 and 210 create pressure vessel206. The o-rings may prevent air from escaping from pressure vessel 206.The pressure vessel is bounded by structure 202 and the o-rings. In someembodiments, the front face of battery 200 as shown and a back face ofbattery 200 are flush against structure 202. O-rings 204 and 210 mayblock areas where air may escape from pressure vessel 206. In variousembodiments, any number of o-rings are positioned between the batteryand structure to provide an airtight seal and create pressure vessel206. As shown, about half of battery 200 is sealed inside pressurevessel 206, including a portion of the battery that comprises anelectrical contact. The electrical contact is in contact with anelectrical contact of structure 202, creating an electrical connection.In some embodiments, battery 200 is configured to release gas intopressure vessel 206, causing a force to build up on latch 208 in theevent the battery malfunctions.

FIG. 2B is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising a latch and o-rings after batteryejection. In the example shown, latch 208 assumes an inverted positioncompared to its position in FIG. 2A. In some embodiments, the latch isconfigured to invert when subjected to a threshold amount of force. Asshown, latch 208 no longer holds battery 200 in position and inelectrical contact with structure 202. In some embodiments, battery 200is ejected such that a pressure vessel no longer exists. In the exampleshown, battery 200 is ejected past o-rings 204 and 210. The o-rings arenot in contact with the battery and a sealed cavity ceases to exist. Theo-rings may be configured to allow the battery to slide past them in theevent the battery is not held in position by another element, such as alatch.

As shown, battery 200 is no longer electrically connected to structure202. In some embodiments, the electrical contact of battery 200 isconfigured to not reestablish an electrical connection with structure202 after ejection, even in the event that battery 200 falls back intostructure 202. In some embodiments, battery 200 is positioned underneathstructure 202 and gravity causes battery 200 to fall from structure 202after latch 208 ceases to hold battery 200 in electrical contact withthe structure. In some embodiments, battery 200 and structure 202 arepositioned on their sides such that battery 200 is ejected to one siderather than ejected down or up from the structure. In some embodiments,pressure from vented gases is sufficient to push battery 200 away froman electrical contact of the structure. For example, the battery may bepushed sufficiently far from an electrical contact of the structure suchthat it will not regain electrical contact.

In some embodiments, latch 208 is a reversible seal. For example, latch208 may be returned to its original position in FIG. 2A. In someembodiments, a reversible seal is used to seal battery replacements thatare put in place after an original battery is ejected.

FIG. 3A is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising bolts prior to battery ejection. Insome embodiments, non-reversible seals are utilized. For example, oncethe seal is broken, it may not be reversed to an original positionwherein it creates an airtight cavity surrounding at least a portion ofthe battery. In the example shown, battery 200 is held in electricalcontact with structure 302 via panel 306. Panel 306 is bolted intostructure 302 using bolts 304 and 308. O-rings 310 and 312 as showncreate an airtight seal with battery 300, creating pressure vessel 314from which air cannot escape.

FIG. 3B is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising bolts after battery ejection. In theexample shown, panel 306 is fractured into multiple pieces. Panel 306may be configured to break under a threshold amount of pressure. Bolts304 and 308 remain intact and hold portions of panel 306 to structure302. In some embodiments, bolts 304 and 306 are configured to shearunder a threshold amount of force. In the event the bolts shear, panel306 may be removed from structure 302 in one piece, causing battery 300to be ejected from its electrical connection. For example, panel 306 andbattery 300 may fall away from structure 302 due to gravity in the eventbattery 300 is positioned below structure 302.

FIG. 4A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising magnets prior to battery ejection. Inthe example shown, battery 400 is completely sealed in pressure vessel414 using panel 406, magnets 404 and 408, and o-rings 410 and 412.Magnets 404 and 408 hold panel 406 against structure 402, keepingbattery 400 in contact with structure 402 at an end of the battery thatcomprises an electrical contact. In the example shown, panel 404 is heldadjacent to structure 402 using magnets 404 and 408, which are attractedto magnets that are embedded in structure 402. In some embodiments, themagnets and panel do not create an airtight seal. O-rings 410 and 412may create an airtight seal with battery 400, creating pressure vessel414. In some embodiments, o-rings or other components are utilized tocreate a smaller pressure vessel than would otherwise be created byusing a seal that encloses the entire battery in the pressure vessel.The positioning of the o-rings or airtight seal component may bedetermined based on a threshold pressure level of the magnets orrestraining component. For example, in the event the magnets aredisplaced only under a force that is much larger than a force that mapsto a dangerous level of gas venting, the o-rings may be positioned tocreate a small pressure vessel. The battery's enclosure or covering mayensure that released gas is released into the pressure vessel. The smallpressure vessel may cause the magnets to be displaced in the event adangerous level of gas venting occurs. In some embodiments, the paneland magnets hold battery 400 in a position wherein an airtight seal iscreated around a portion of the battery using o-rings 410 and 412.

FIG. 4B is a flow diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising magnets after battery ejection. Insome embodiments, magnets 404 and 408 are configured to separate frommagnets embedded in structure 402 when subjected to a threshold force.In the example shown, magnets 404 and 408 have separated from magnetsembedded in structure 402, causing panel 406 to be removed from itsprior position. As shown, panel 406 is not in contact with structure402, allowing battery 400 to be ejected from its electrical connection.

In various embodiments, reversible or irreversible seal components areutilized in various positions around a battery. In some embodiments,seal components are used only between the battery and an electrical loadthe battery powers. For example, in lieu of o-rings between battery 400and structure 402, a magnet may be used that is dislodged from itsposition with a specified amount of force. A latch may be used between abattery and an electrical load the battery provides power to create anairtight cavity. In some embodiments, seal components are used onlyexternally on the battery and powered electrical load. For example, abattery may be completely enclosed in a pressure vessel constrained by aseal. In some embodiments, a combination of seal components in variouspositions is used.

FIG. 5A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising shear o-rings prior to batteryejection. In the example shown, shear o-rings 504 and 506 are positionedon either side of battery 500. The shear o-rings are positioned betweenthe battery and structure 502. In some embodiments, the shear o-ringseach comprise two flexible o-rings connected by a component that shearsunder a threshold force. In some embodiments, the component consists ofa brittle material. In the example shown, structure 502 and battery 500are shaped to accommodate the shear o-rings. Pressure vessel 508comprises an airtight cavity bounded by shear o-rings 504 and 506,battery 500, and structure 502. In some embodiments, shear o-rings 504and 506 hold battery 500 in a position wherein the battery is inelectrical contact with structure 502.

FIG. 5B is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising shear o-rings after battery ejection.In the example shown, the component that connects the o-rings of eachshear o-ring has broken due to pressure created by vented gases. Asshown, o-rings 510 and 512 previously of shear o-rings 504 and 506respectively remain positioned in a covering of the battery. Forexample, o-rings 510 and 512 remain positioned lodged in indents of acan battery 500 is stored in. O-rings 514 and 516 previously of shearo-rings 504 and 506 respectively remain positioned lodged in indents ofstructure 502. Battery 500 is ejected from its electrical connectionwith structure 502.

FIG. 6A is a diagram illustrating an embodiment of a pressure-basedbattery ejection system which includes an orifice in the pressurecavity. In the example shown, battery 600 is held in position via latch602 while o-rings 604 and 606 create an airtight seal to pressure vessel608. In the example shown, pressure vessel 608 comprises orifice 610. Invarious embodiments, pumps or venturis connected to the orifice are usedto modify a pressure level inside the pressure vessel or extract vaporsamples for battery health monitoring.

In some embodiments, pressure inside pressure vessel 608 is regulated tochange characteristics of the battery ejection so that system can beused with different types of batteries which vent gases at differentrates. For example, a vacuum or pressure-regulating device attached atorifice 610 may be used to calibrate or adjust the pressure inside thepressure vessel so that the battery is ejected at whatever pressurelevel corresponds to an unsafe and/or undesirable level. Alternatively,in lieu of pressure regulation (e.g., for systems which do not include avacuum or pressure-regulating device), latch 602 may be released whilebattery 600 is still safe to use. For example, the latch may be releasedwhen battery 600 is venting at low levels if there is no pressureregulation.

In an aircraft application, a pressure-regulating device may equalizepressure inside the pressure vessel to match pressure outside theaircraft via the orifice. In some embodiments, the pressure-regulatingdevice ensures that pressure changes due to altitude do not cause theseal of the pressure vessel to release. Over long time scales, thepressure-regulating device may cause pressure to equalize, whereas asudden venting of gas caused by battery malfunction cannot be equalizedquickly enough by the pressure-regulating device and the seal isreleased.

In some embodiments, an interior of the pressure vessel or cavitycomprises a thermally resistant coating. Gases released during batterymalfunction may be hot. In some embodiments, the coating is ablative andvaporizes when subjected to heat. Vapors created by the coating may beaccounted for in calibrating the seal for properly timed batteryejection.

FIG. 6B is a diagram illustrating an embodiment of a pressure-basedbattery ejection system comprising an exhaust monitor. In someembodiments, an exhaust monitor is used to analyze gas in the pressurevessel. In the example shown, exhaust monitor 612 analyzes gas frompressure vessel 608 via a tube that connects the exhaust monitor to thepressure vessel. The exhaust monitor may determine whether battery 600is (e.g., abnormally and/or dangerously) venting gas based on thecomposition of gas in the pressure vessel. For example, malfunctioningbatteries release electrolytes of specific compositions. In the eventexhaust monitor detects the electrolytes in the pressure vessel, thebattery may be determined to be (e.g., abnormally and/or dangerously)venting and responsive actions may be performed. In some embodiments, awarning is automatically delivered to relevant systems or persons in theevent the battery is determined to be venting. For example, a pilot orautopilot system of an aircraft is automatically and/or in advancewarned via an aircraft application of the system. In some embodiments,the pressure-based battery ejection system is calibrated to eject aventing battery only when a volume of released gases indicates thebattery cannot be used any longer, which is designed to occur after theindicative electrolytes have been detected. However, a battery that hasstarted to vent or is venting a low volume of gas may provide an (e.g.,early) indication to a pilot or autopilot that the aircraft should belanded soon or power intensive aircraft maneuvers should be avoided. Insome embodiments, the exhaust monitor is part of a suite of batterymanagement elements. In some embodiments, a pilot or autopilot forciblyejects a battery based on information collected by the exhaust monitor.For example, batteries of the pressure-based battery ejection system canbe actively ejected in addition to passively ejected due to pressure.

FIG. 7 is a flow diagram illustrating an embodiment of an exhaustmonitoring process. At 700, gas in the pressure vessel is analyzed. At702, it is determined whether threshold levels of venting gases aredetected. In some embodiments, various types of gases have differentthreshold levels. Multiple gases may be required to be detected abovetheir respective threshold levels. In the event threshold levels ofventing gases are not detected, gas in the pressure vessel continues tobe analyzed. In the event threshold levels of venting gases aredetected, at 704 a warning is provided to a pilot. In some embodiments,a battery corresponding to the pressure vessel is actively ejected inthe event a second higher threshold level of venting gases is detected.

FIG. 8A is a diagram illustrating an embodiment of a spring contactelectrical connection. In various embodiments, the battery is connectedto the rest of the electrical system using various configurations ofelectrical contacts. In some embodiments, the electrical contacts aredesigned to establish an electrical connection that is easilydisconnected. For example, the electrical contacts will not continue tohold the battery in place after the seal of the pressure vessel isreleased. In some embodiments, the electrical contact of the battery andthe electrical contact of the electrical load are configured todisconnect in the event some pushing or pulling force causes theelectrical contacts to electrically and/or physically disconnect. In theevent the battery is subjected to a force (e.g. pressure from gasbuild-up or gravity) that causes it to lose contact with the electricalload, the electrical connection is broken. In some embodiments, theelectrical contact of the battery must be subjected to a force thatpushes it firmly against the electrical contact of the electrical load,otherwise the electrical connection is broken.

In the example shown, battery 800 includes plate 802. Plate 802 is inelectrical contact with spring-loaded contact 804. In the event theplate and spring are no longer touching, the electrical connection isbroken.

In some embodiments, a pogo pin is used for spring-loaded contact 804.In the event a spring of the pogo pin is compressed, the electricalconnection is complete. In the event the pogo pin is not compressed, theelectrical connection is broken. In some embodiments, the battery isheld in a position that compresses the pogo pin in the event the seal isintact.

In some embodiments, the electrical contact is designed such that anelectrical connection will not reconnect or reform after batteryejection. For example, the spring of the pogo pin may be able towithstand the weight of the battery. In the event the battery is ejectedup from the structure and falls back down, the weight of the batterywould not be sufficient to reform the electrical connection. In someembodiments, a seal (e.g. a bolt, a latch, or a magnet) must be replacedto reform the electrical connection.

FIG. 8B is a diagram illustrating an embodiment of a blade and springelectrical connection. In the example shown, battery 820 includes blades822 and 824. The blades extrude from the battery. The blades are inelectrical contact with springs 826 and 828 (sometimes referred to as aclip). Spring 826 comprises two pins that blade 822 slides in between.In some embodiments, the pins of spring 826 are tensioned to hold blade822 securely and create a secure electrical connection. Blade 824 issituated in between two pins of spring 828. In the event battery 820 isejected, blade 822 and 824 may slide out from springs 826 and 828. Asshown here, in various embodiments, various types of electrical contactsare used.

FIG. 9 is a diagram illustrating an embodiment of an aircraft whichincludes a pressure-based battery ejection system. In the example shown,aircraft 900 includes (forward) wing 918 and (rear) wing 936. Wing 918includes pylons 908 and 916, on either side of the fuselage. Pylon 908includes rotor 902 and rotor engine 904. Pylon 908 also includes eightbatteries, including battery 906. In various embodiments, 4, 10, 12, orany appropriate number of batteries are stored in a single pylon. Pylon916 includes rotor 910 and rotor engine 912. Pylon 916 also includeseight batteries, including battery 914. Wing 936 includes pylons 926 and934, on either side of its fuselage. Pylon 926 includes rotor 920 androtor engine 922. Pylon 926 also includes eight batteries, includingbattery 924. Pylon 934 includes rotor 928 and rotor engine 930. Pylon934 also includes eight batteries, including battery 932.

In this example, the pressure-based battery ejection system is installedon each battery shown. For example, battery 906 is stored at leastpartially within a sealed cavity, wherein a seal on the cavity isconfigured to release in the event a threshold level of pressure isreached within the sealed cavity. In some embodiments, the batteries arepositioned such that an end of the battery that does not have anelectrical contact faces downwards towards the ground in normal flight.For example, a latch or panel may be positioned below the battery andhold the battery in place. In the event the latch or panel releases, thebattery is dropped and ejected from its electrical connection. Thebattery may be ejected from its electrical contact via gravity followingthe release of the seal. In some embodiments, the battery is ejectedfrom its electrical connection but remains in the aircraft. In someembodiments, the battery is ejected completely from the aircraft. In theevent the battery is ejected from the aircraft, the aircraft maycomprise safety mechanisms to prevent the battery from becoming aprojectile. For example, the battery may be attached to the aircraft viaa tether.

In some embodiments, the batteries are positioned to be ejected upwardsfrom the aircraft or laterally in parallel with the aircraft's wings.For example, a battery may be ejected upwards from the aircraft. Thebattery may comprise an electrical contact that will not establish anelectrical connection with the aircraft after ejection. The battery maybe ejected out to one side of the aircraft rather than downwards.

In some embodiments, the pressure-based battery ejection system ispermitted to eject a central or primary battery of an aircraft if/whenappropriate. Alternatively, in some embodiments, the system is onlypermitted to eject batteries that do not have a significant impact onthe aircraft's center of gravity or power levels if/when appropriate.For example, the ejection system is only coupled to smaller or outboardbatteries wherein the ejection of the batteries does not have a severeadverse effect on flight.

In some embodiments, a battery of the pressure-based battery ejectionsystem is configured to allow vented gases to escape from the batteryquickly in the event the battery is disconnected from all electricalconnections.

FIG. 10 is a diagram illustrating an embodiment of a barrier betweenbatteries. In some embodiments, multiple batteries implementing thepressure-based battery ejection system are positioned next to each other(see, e.g., how multiple batteries are stored in the same pylon in FIG.9). In some embodiments, a barrier is positioned between batteries. Thebarrier prevents heat transfer between batteries. For example, barriers1000, 1010, and 1016 may comprise fire-retardant divisions. The barriersprevent hot gas released from battery 1002 from heating up battery 1012.Excessive heat from one battery may cause an adjacent battery tocatastrophically fail, creating a domino effect of failing batteries andfire-retardant divisions would prevent this from happening. In theexample shown, battery 1002 and battery 1012 are positioned inalignment. For example, latches 1004 and 1014 are in parallel.

FIG. 11A is a diagram illustrating an embodiment of a latch prior tobattery ejection. Ejecting multiple adjacent batteries may cause anunsafe change to a center of gravity of a vehicle or aircraft. In someembodiments, ejecting two or more adjacent batteries causes that sectionof the aircraft to be dangerously underpowered. The weight or powerchanges that occur due to ejecting multiple batteries in close proximitymay pose more danger than continuing to use the venting batteries. Insome embodiments, mechanical means are used to prevent a battery fromejecting in the event an adjacent battery has already been ejected. Inthe example shown, battery 1100 is held in position via L-shaped latch1102. The latch is used in conjunction with o-rings. Adjacent battery1104 is sealed partially in a pressure vessel utilizing o-rings andL-shaped latch 1106.

FIG. 11B is a diagram illustrating an embodiment of a deployed latchthat prevents a neighbor battery from ejecting. In the example shown,L-shaped latch 1102 has released, allowing 1100 to be electricallydisconnected. L-shaped latch 1102 is now in a position where itrestrains battery 1104. In the event latch 1106 releases, battery 1104will remain electrically connected to the electrical load it powers dueto latch 1102.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, the invention is not limitedto the details provided. There are many alternative ways of implementingthe invention. The disclosed embodiments are illustrative and notrestrictive.

What is claimed is:
 1. A battery ejection system, comprising: a cavitystructure sized to hold at least one battery, wherein: a first wall ofthe cavity structure contacts a surface of the at least one battery viaa first sealing member; a second wall of the cavity structure contactsanother surface of the at least one battery via a second sealing member;and a third wall of the cavity structure includes an electricalconnection; a battery submodule positioned at least partially in thecavity structure, the battery submodule including the at least onebattery that releases gas and disconnects from the electrical connectionof the third wall of the cavity structure; and a seal including thefirst sealing member and the second sealing member, wherein the seal isconfigured to: in a first mode, form a pressure vessel in a spacebetween the third wall of the cavity structure and a first portion ofthe battery submodule by sealing off the space between the cavitystructure and the first portion of the battery submodule, wherein theseal is positioned near the midsection of the at least one battery inthe event that the pressure vessel is formed; and in a second mode:release, in response to gas released by the at least one battery causesa pressure level in the pressure vessel to exceed a threshold pressurelevel, wherein the threshold pressure level corresponds to an amount ofpressure that the seal of the cavity is designed to handle beforereleasing, wherein in the event that the at least one battery releasesgas, the at least one battery releases gas towards the third wall, andwherein a force of the released gas pushes the at least one battery outof the cavity in the event that the gas released by the at least onebattery causes the pressure level in the pressure vessel to exceed thethreshold pressure level; and cause the battery submodule to be ejectedin response to a force of pressure buildup of the gas released by the atleast one battery.
 2. The system of claim 1, wherein the batterysubmodule releases gas into the pressure vessel in the event the batterysubmodule malfunctions.
 3. The system of claim 1, wherein the batterysubmodule comprises a covering that directs gas released by the batterysubmodule.
 4. The system of claim 1, wherein in the first mode, thebattery submodule is electrically connected to an electrical load via anelectrical contact of the battery submodule, wherein the electricalconnection of the third wall of the cavity structure is an electricalcontact of the electrical load.
 5. The system of claim 4, wherein theelectrical load comprises an aircraft or other vehicle.
 6. The system ofclaim 4, wherein the electrical contact of the battery submodule and theelectrical contact of the electrical load are configured to disconnectin the event the at least one battery is subjected to a force directedin a direction opposite from the electrical contact of the electricalload.
 7. The system of claim 6, wherein in the second mode, the forcedirected in the direction opposite from the electrical contact of theelectrical load is exerted due to a build-up of pressure in the pressurevessel or due to gravity.
 8. The system of claim 6, wherein theelectrical contact of the battery submodule comprises a pogo pin.
 9. Thesystem of claim 4, wherein in the first mode, the seal exerts a force onthe battery submodule that pushes the electrical contact of the batterysubmodule against the electrical contact of the electrical load.
 10. Thesystem of claim 1, wherein in the first mode, the seal causes thepressure vessel to be airtight.
 11. The system of claim 1, wherein theseal is configured to shear under the threshold pressure level.
 12. Thesystem of claim 1, wherein the seal comprises a bistable seal that isconfigured to change from a first state to a second state when subjectedto the threshold pressure level.
 13. The system of claim 1, wherein theseal comprises a latch, an o-ring, a magnet, or a bolt.
 14. The systemof claim 1, wherein the seal comprises a first component that exerts aforce on the battery submodule that pushes an electrical contact of thebattery submodule against an electrical contact of an electrical loadand a second component that creates an airtight seal between the batterysubmodule and the electrical load, forming the pressure vessel.
 15. Thesystem of claim 14, wherein a latch is used to hold the batterysubmodule in electrical contact with the electrical load and an o-ringis used to create an airtight seal between the battery submodule and theelectrical load.
 16. The system of claim 1, wherein the pressure vesselcomprises an orifice.
 17. The system of claim 16, wherein a pressureregulator or vacuum is attached via the orifice.
 18. The system of claim16, wherein a gas monitor is attached via the orifice.
 19. The system ofclaim 18, wherein a warning is automatically delivered to an operator,pilot, or system in the event the battery is determined to be releasinggas based on the gas monitor.
 20. The system of claim 1, wherein thebattery ejection system is provided in a pylon included in a wing of avehicle.
 21. The system of claim 1, wherein the battery submodule ispositioned fully within the cavity structure in the first mode, and thesystem further comprises: at least one magnet; and a panel, wherein theat least one magnet holds the panel against the cavity structure suchthat the battery submodule and the cavity structure maintain contact inthe first mode.
 22. The system of claim 1, wherein the seal is alignedat one end of the battery submodule leaving a second portion of thebattery submodule unsealed.